ReadingComprehension(90minutes)Directions:Thereare4passagesinthissection.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).YoushoulddecideonthebestchoiceandmarkthecorrespondingletteronAnswerSheet.PassageOneQuestions1to5arebasedonthefollowingpassage.Althoughmanyofusmayfeelair-conditionersbringrelieffromhot,humidorpollutedoutsideair,theyposemanypotentialhealthhazards.Muchresearchhaslookedathowthemovementofairinsideaclosedenvironment---suchasanofficebuilding---canspreaddiseaseorexposepeopleinthebuildingtoharmfulchemicals.OneofthemorewidelypublicizeddangersisthatofLegionnaire’sdisease,whichwasfirstrecognizedinthe1970s.Thiswasfoundtohaveaffectedpeopleinbuildingswithair-conditioningsystemsinwhichwarmairpumpedoutofthesystem’coolingtowerswassomehowsuckedbackintotheairintake(通风口),inmostcasesduetopoordesign.Thewarmair,filledwithbacteria,wascombinedwithcooled,conditionedairandwasthencirculatedaroundvariouspartsofthebuilding.Studiesshowedthatevenpeopleoutsidesuchbuildingswereatriskiftheywalkedpastairexhaustpipes.Largeair-conditioningsystemsaddwatertotheairtheycirculatebymeansofhumidifiers(湿度调节器).Inoldersystems,thewaterusedforthisprocessiskeptinspecialreservoirs,thebottomsofwhichprovidebreedinggroundsforbacteriawhichcanfindtheirwayintotheventilation(通风)system.Therisktohumanhealthfromthissituationhasbeenhighlightedbythefactthattheimmunesystems(免疫系统)ofapproximatelyhalfofworkersinair-conditionedofficebuildingshavedevelopedtheabilitytofightofftheorganismsfoundatthebottomofsystemreservoirs.Butchemicalscalled“biocides”areaddedtoreservoirstomakethemgerm-free,andtheyaredangerousintheirownrightinsufficientquantities,astheyoftencontaincompoundsstronglylinkedtocancers.Finally,itshouldbepointedoutthattheartificialclimaticenvironmentcreatedbyair-conditionerscanalsoaffectus.Inanaturalenvironment,whetherindoororoutdoor,therearesmallvariationsintemperatureandhumidity.Indeed,thehumanbodyhaslongbeenaccustomedtothesenormalchanges.Inanair-conditionedlivingorworkingenvironment,however,bodytemperaturesremainwellunder37℃,ournormaltemperature.Thisleadstoaweakenedimmunesystemandthusgreaterexposuretodiseasessuchascoldsandflu.1.WhatdoweknowaboutLegionnaire'sdiseasefromthepassage?
A
It was the most widely
concerned office hazard.
B
It happens only in
air-conditioned office buildings.
C
It can affect people both inside and outside the building.
D
It does not develop in well-designed buildings.